This invention relates of the heating of relatively large bodies of water for swimming pools, water spas, hydrotherapy equipment and whirlpools.
Heating apparatus for water, especially for outdoor use, has been very expensive and wasteful in regard to energy consumption. Often, water heaters store substantial amounts of water, maintained at an elevated temperature, to provide for more rapid heating or fireup. Such heaters must, therefore, be of a large size and involve costly installation and maintenance. It is, therefore, an important object of the present invention to provide a water heater which occupies less space and operated to maintain a desired water temperature by a more efficient expenditure of electrical energy. A further object is to provide a water heater that is easy to install and requires a minimum of maintenance.